FIG. 4 illustrates an example of a conventional semiconductor light emitting device (see Patent Document 1 identified below, for example). The semiconductor light emitting device X illustrated in the figure includes a substrate 91 and three semiconductor light emitting elements 93R, 93G, 93B mounted on the main surface of the substrate 91. Specifically, the substrate 91 is provided with electrodes 92R, 92G, 92B on which the semiconductor light emitting elements 92R, 92G, 92B are bonded, respectively. The substrate 91 is further provided with a common electrode 92C, to which the semiconductor light emitting elements 93R, 93G, 93B are electrically connected via wires. The semiconductor light emitting elements 93R, 93G, 93B are surrounded by a case 95 made of a resin. The semiconductor light emitting device X is designed as a side-view type light emitting device to be mounted on e.g. a printed circuit board with a longitudinal side surface of the substrate 91 utilized as the mount surface.                Patent Document 1: JP-A-2006-24794        
In recent years, there is a demand for size reduction of semiconductor light emitting devices. As to the side-view type semiconductor light emitting device described above, it is demanded to reduce the projecting amount (i.e., height) of the light emitting device from the printed circuit board on which the light emitting device is mounted. However, the reduction of the projecting amount means the reduction of the area of the main surface of the substrate 91, i.e., the reduction of the space required for placing the semiconductor light emitting elements 93R, 93G, 93B and the wires connected to the light emitting elements. Generally, as the space becomes narrower, it becomes more technically difficult to arrange necessary circuits in the space. Thus, with the conventional structure of the semiconductor light emitting device X, there is a limit on the size reduction.